Diisopropylamine → HCID 18999057, compound

Participants

Reaction Steps

n-Butyllithium (17.5 ml of a 1.6M hexane solution)in anhydrous tetrahydrofuran (20 ml) was added dropwise to a stirred, cooled (-72° C.) solution of diisopropylamine (3.8 ml) in anhydrous tetrahydrofuran (120 ml) under a nitrogen atmosphere. 5-Bromo-2-methoxypyridine (5.09 g, Eur. J. Med. Chem. 1977, 12, 531) in anhydrous tetrahydrofuran (15 ml) was added dropwise followed by a solution of 2-nitrobenzaldehyde (2.96 g) in anhydrous tetrahydrofuran (20 ml) keeping the temperature of the reaction mixture below -70° C. The reaction mixture was stirred for 3 hours at -60° C. to -70° C. then quenched with saturated aqueous ammonium chloride solution. The organic layer was separated, washed with water then dried (magnesium sulphate) and evaporated to dryness. The residue was combined with crude product from another reaction of identical scale then purified by column chromatography on silica using ethyl acetate/petroleum ether (60-80) (1:4) and the solid obtained recrystallised from dichloromethane/petroleum ether (60-80) to afford the title compound (8.69 g). mp 128°-131° C. Rf =0.69 in 20% diethyl ether/dichloromethane on silica plates; 1H NMR (360 MHz, CDCl3) δ 3.93 (3H, s), 6.42 (1H, s), 7.00 (1H, s), 7.31 (1H, dd, J=1 and 7 Hz), 7.49 (1H, ddd, J=1 and 7 Hz), 7.58 (1H, ddd, J=1 and 7 Hz), 8.02 (1H, dd, J=1 and 7 Hz), 8.19 (1H, s); IR (KBr) 3600-2800 cm-1.

Provenance & Evidence